The use of fatty acids for preventing and/or treating inflammation in superficial tissues has been described in the literature.
For example, EP 5 472 705 (Prospa B. V.) discloses new pharmaceutical compositions for topical use containing esters of .omega.-3 polyunsaturated acids in a high concentration and intended for treating psoriasis, phlebitis and related pathologies.
EP 582 239 (Rhone-Poulenc Rorer) discloses topical pharmaceutical and cosmetic compositions containing linoleic acid or derivatives thereof as active ingredients, and a carrier for transporting the active ingredient into the skin. These compositions are used for the prophylaxis and treatment of impure skin, e.g. skin affected by pimples, pustules, urticaria or comedones, of acne and of acne-associated skin disorders.
Furthermore, EP 5 312 834 (Woobang Land Co.) discloses a pharmaceutical composition for treating acne comprising eicosapentaenoic acid and (.alpha.-linolenic acid, in a weight ratio of 1:0.1 to 20:0.1 of eicosapentaenoic acid to .alpha.-linolenic acid respectively. These fatty acids may be extracted from natural substances such as fish oil and/or perilla oil, for example.
The term non-methylene-interrupted fatty acid, the acronym for which is NMIFA, refers to a fatty acid with a series of double bonds in which at least one adjacent pair of double bonds is separated by at least two carbon atoms, i.e., by a group other than a single methylene group. NMIFAs have been the subject of only a few studies with the aim of developing an understanding of their incorporation into mammalian tissues and their potential role in the treatment of certain diseases.
For example, JP 61 058 536 (Nippon Oil) discloses a method for purifying pine nut oil containing at least 10% by weight of 5,9,12-cis-octadecatrienoic acid which exhibits a curative effect against arterial hypertension. WO 96 05 164 (Broadben Nominees Pty) discloses an anti-inflammatory preparation comprising a purified active fraction, for example 5,11,14,17-eicosatetraenoic acid, isolated from a lipid extract of Perna canalicullus or Mytilus edulis.
WO 95 17 987 (The Regents of the University of California) shows that broad class of NMIFAs, including 5,11,14-eicosatrienoic acid, may be used in an effective amount for suppressing autoimmune diseases in general, for example rheumatoid arthritis, lupus erythmatosis, multiple sclerosis, myasthenia gravis, and about 30 other diseases currently known.
Incorporation of dietary 5,11,14-eicosatrienoate into various mouse phospolipid classes and tissues has been studied. Results show that feeding the mice 5,11,14-eicosatrienoate resulted in lower levels of 20:4n-6 in the hepatic phosphatidylinositol pool. Because leukotrienes and prostaglandins cannot be formed from 5,11,14-eicosatrienoate due to the lack of an internal .DELTA.8 double bond, and because 20:4n-6 was dramatically reduced in some phosphatidylinositol pools, it was expected that dietary intake of 5,11,14-eicosatrienate may alter eicosanoid metabolism, thus reducing potential inflammation in the hepatic system (Biochemica et Biophysica Acta, 1085, 371-376, 1991; J. Nutr. Biochem., 4, 409-420,1993).
So far, the following class of NMIFAs, especially 5,11,14-eicosatrienoic acid has not been reported as being capable of being incorporated into the lipid fraction of superficial mammalian tissues. Neither has an anti-inflammatory effect in superficial mammalian tissues been expected.